Methods: We performed a prospective, randomized trial in an intensive care unit (ICU) in a tertiary care center. In this study, 42 patients (American Society of Anesthesiology physical status I and II) who underwent scoliosis surgery were divided into 2 groups according to sedation protocols: group DEX (n = 22) and group MDZ (n = 20). Children (12-18 years) requiring mechanical ventilation underwent a continuous infusion of either dexmedetomidine (group DEX; starting dose, 0.4 μg•kg-1•h-1) or midazolam (group MDZ; starting dose, 0.1 mg•kg-1•h-1) with intermittent fentanyl, as needed. The efficacy of sedation was assessed using the Richmond Agitation Sedation Scale (RASS). Quality of pain relief was measured using the Numeric Visual Analog Scale (NVAS). During the arousal assessment, delirium was determined in patients in the RASS range of -2 to +1 using the Confusion Assessment Method for the ICU (CAM-ICU). Fentanyl consumption, incidence of delirium, NVAS scores, and hemodynamics were recorded postoperatively at 2, 4, 6, and 24 h in the ICU.